As the paragraph descriping shows that 123770-62-7 is playing an increasingly important role.
With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.123770-62-7,Ethyl 5-(hydroxymethyl)isoxazole-3-carboxylate,as a common compound, the synthetic route is as follows.
Ethyl chlorooximidoacetate (10 g, 66 mmol) in CHCl3 (80 mL) is slowly added to propargyl alcohol (4.7 mL, 81 mmol) and K2CO3 (27 g, 198 mmol) in CHCl3 (80 mL). The addition is accompanied by an exothermic reaction which causes the chloroform to reflux. After being allowed to cool to RT, the mixture is stirred overnight. The reaction mixture is filtered and the residue is rinsed with chloroform and concentrated in vacuo. The crude product is purified by chromatohraphy (Biotage 40M, EtOAc/Hex:20/80) to yield 3.23 g (29% yield) of ethyl 5-(hydroxymethyl)isoxazole-3-carboxylate as an oil. 1H NMR (400 MHz, CDCl3) delta 6.69, 4.86, 4.45, 4.42. A solution of diethylaminosulfur trifluoride (DAST) (2.8 mL, 21 mmol) in 30 mL CH2Cl2 is added dropwise to a solution of ethyl 5-(hydroxymethyl)isoxazole-3-carboxylate (3.0 g, 18 mmol) in 30 mL CH2Cl2 at -78 C. The mixture is stirred at -78 C. for 1 h and then warmed to RT over 3 h. Water (10 mL) and 30 mL of 2.5% aqueous sodium bicarbonate solution are added successively and the organic layer is separated, dried (MgSO4) and evaporated in vacuo. The residue is purified by chromatography (Biotage 40M, EtOAc/Hex:20/80) to give 1.83 g (60% yield) of ethyl 5-(fluoromethyl)isoxazole-3-carboxylate as an oil. 1H NMR (400 MHz, CDCl3) delta 6.82, 5.54, 5.42, 4.47, 1.43. 10% Aqueous sodium hydroxide solution (5 mL) is added to a solution of ethyl 5-(fluoromethyl)isoxazole-3-carboxylate (1.82 g, 10 mmol) in ethanol (30 mL) at RT. The mixture is stirred for 2 h and the solvents are evaporated in vacuo. The residue is dissolved in water and acidified to pH 1 with 35% HCl. Ethanol is added, solvents are evaporated in vacuo and the residue is azeotroped with ethanol. Ethanol is added and the mixture filtered to remove inorganic solids. Evaporation in vacuo of the filtrate gives 0.95 g (63% yield) of 5-(fluoromethyl)isoxazole-3-carboxylic acid as a tan solid. 1H NMR (400 MHz, DMSO-d6) delta 7.05, 5.67, 5.56. Oxalyl chloride (0.85 mL, 9.8 mmol) is added dropwise to a suspension of 5-(fluoromethyl)isoxazole-3-carboxylic acid (0.94 g, 6.5 mmol) and a catalytic amount of DMF in 20 mL CH2Cl2. After 1 h, the volatiles are removed in vacuo and the remaining residue is dissolved in acetone. To this solution is added an aqueous solution of sodium azide (0.59 g, 9.1 mmol) at 0 C. with vigorous stirring. Volatiles are removed in vacuo and the residue washed with water and dried under nitrogen to yield 0.57 g (51% yield) of 5-(fluoromethyl)isoxazole-3-carbonyl azide as a white solid. 1H NMR (400 MHz, DMSO-d6) delta 7.21, 5.71, 5.59. Example 605 is prepared according to Method F, making non-critical modifications. Yield 37%. HRMS (ESI) calcd for Cl3H13ClFN3O4+H 330.0657 found 330.0649
As the paragraph descriping shows that 123770-62-7 is playing an increasingly important role.
Reference£º
Patent; Piotrowski, David W.; Rogers, Bruce N.; McWhorter JR., William W.; Walker, Daniel Patrick; Corbett, Jeffrey W.; Groppi JR., Vincent E.; Rudmann, Daniel G.; US2003/236287; (2003); A1;,
Isoxazole – Wikipedia
Isoxazole | C3H3NO – PubChem